iwlwifi: mvm: Add mem debugfs entry

In order to access cached/paged memory, there are a couple of firmware
commands (one for UMAC and one for LMAC) that let the host access memory
and registers indirectly. Since this is done by the firmware on behalf
of the host, even if memory is paged out or cached, the host will
retrieve the memory as the firmware sees it (paged out memory will get
paged in).

Export this mechanism via a debugfs entry for both read and write
access.

WARNING: This mechanism has no protections at all. Invalid addresses may
crash or hang the firmware. Writing to arbitrary memory also comes with
no guarantees.

Signed-off-by: Ido Yariv <idox.yariv@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw-api.h b/drivers/net/wireless/intel/iwlwifi/mvm/fw-api.h
index 2f92994d0e5b..fdd9506e10cd 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw-api.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw-api.h
@@ -340,6 +340,11 @@ enum iwl_prot_offload_subcmd_ids {
 	STORED_BEACON_NTF = 0xFF,
 };
 
+enum iwl_fmac_debug_cmds {
+	LMAC_RD_WR = 0x0,
+	UMAC_RD_WR = 0x1,
+};
+
 /* command groups */
 enum {
 	LEGACY_GROUP = 0x0,
@@ -349,6 +354,7 @@ enum {
 	PHY_OPS_GROUP = 0x4,
 	DATA_PATH_GROUP = 0x5,
 	PROT_OFFLOAD_GROUP = 0xb,
+	DEBUG_GROUP = 0xf,
 };
 
 /**
@@ -2149,4 +2155,48 @@ struct iwl_channel_switch_noa_notif {
 	__le32 id_and_color;
 } __packed; /* CHANNEL_SWITCH_START_NTFY_API_S_VER_1 */
 
+/* Operation types for the debug mem access */
+enum {
+	DEBUG_MEM_OP_READ = 0,
+	DEBUG_MEM_OP_WRITE = 1,
+	DEBUG_MEM_OP_WRITE_BYTES = 2,
+};
+
+#define DEBUG_MEM_MAX_SIZE_DWORDS 32
+
+/**
+ * struct iwl_dbg_mem_access_cmd - Request the device to read/write memory
+ * @op: DEBUG_MEM_OP_*
+ * @addr: address to read/write from/to
+ * @len: in dwords, to read/write
+ * @data: for write opeations, contains the source buffer
+ */
+struct iwl_dbg_mem_access_cmd {
+	__le32 op;
+	__le32 addr;
+	__le32 len;
+	__le32 data[];
+} __packed; /* DEBUG_(U|L)MAC_RD_WR_CMD_API_S_VER_1 */
+
+/* Status responses for the debug mem access */
+enum {
+	DEBUG_MEM_STATUS_SUCCESS = 0x0,
+	DEBUG_MEM_STATUS_FAILED = 0x1,
+	DEBUG_MEM_STATUS_LOCKED = 0x2,
+	DEBUG_MEM_STATUS_HIDDEN = 0x3,
+	DEBUG_MEM_STATUS_LENGTH = 0x4,
+};
+
+/**
+ * struct iwl_dbg_mem_access_rsp - Response to debug mem commands
+ * @status: DEBUG_MEM_STATUS_*
+ * @len: read dwords (0 for write operations)
+ * @data: contains the read DWs
+ */
+struct iwl_dbg_mem_access_rsp {
+	__le32 status;
+	__le32 len;
+	__le32 data[];
+} __packed; /* DEBUG_(U|L)MAC_RD_WR_RSP_API_S_VER_1 */
+
 #endif /* __fw_api_h__ */